Pulmonary artery catheter (PAC) insertion in patients with severe pulmonary hypertension, right heart dilation and failure, is very challenging. Misplacement and knotting are rare but could be serious complications leading to a delay of the monitoring and sometimes an emergent not expected intervention. Here we report a case of a patient admitted to Intensive Care Unit (ICU) with an acute hypoxemic respiratory failure. She had a history of chronic respiratory failure with pulmonary hypertension and right heart failure. We decided to monitor her cardiac output and pulmonary pressure with a PAC. Repeated attempts to reach the pulmonary artery (PA) were unsuccessful and the PAC was knotted and blocked at the distal tip of the introducer. Under fluoroscopy the knot was released by radiologist. Few days later, a monitoring of PA pressure was needed to guide a PA vasodilator treatment. Under fluoroscopic guidance with the supervision of radiologist, the catheter was successfully placed in the PA at the first attempt. Despite some limitations (patient displacement and radiation), this technique is more accurate than waveform guidance. We suggest in specific situations (low cardiac output, severe pulmonary hypertension, and severe tricuspid regurgitation) to consider first fluoroscopy.